How long after exp. can print last without dev?

EKDobbs · Feb 8, 2012

So, I've got a weird situation. I have a darkroom at school, but I can only be there during school hours. I have a free period, but that's only an hour and a half. What I'd like to be able to do is expose prints during lunch, then process them in my free period about two hours later. The paper will of course be stored in total darkness until it's processed. Even still, will waiting this long degrade the image?

brianmquinn · Feb 8, 2012

It will work. It is sort of like shooting film today and developing the roll 2 weeks later. However paper is a little more sensitive. I would not wait 2 weeks to develop it. Actually I would not wait even a full day. I have done this test myself. If expose 2 sheets of paper the same way. Like a 10 second exposure of a negative at F16 and develop one sheet right away and put the other sheet away and develop it a day later in FRESH DEVELOPER the two pints look different. Not bad but different.

keithwms · Feb 8, 2012

Days or more should be fine. No problem.

Bob-D659 · Feb 8, 2012

Pretty sure I saw something about that on Ilford Photo's website, have a look around there. IIRC, a few hours is ok.

Leigh B · Feb 8, 2012

The latent image on film can remain viable for months, or even years with some degradation (not recommended).

I've never seen a discussion of the latent image on paper. Since paper chemistry is similar to film, I think several days would be no problem.

Just make sure you don't use a "developer-incorporated" paper. Otherwise it might start without you. ;-)

- Leigh

Photo Engineer · Feb 8, 2012

The latent image keeping of paper is generally not as good as that of film. Film was designed to last years with little or no change. I have seen paper that changes from first to last print in a group of 10 processed at once after the last sheet was exposed.

It varies with paper.

It also can change either speed or contrast or both. I suggest that the only way to know for sure is to test.

PE

eddie · Feb 8, 2012

My experience is as PE reports. I've seen changes while bulk processing 5-10 sheets at a time, after the last sheet was exposed. It happened with Ilford MG IV and warmtone fiber papers. I now limit exposure to 3 sheets in succession, before processing. Even with 5-10 sheets, processing began within 10-15 minutes of the first sheet's exposure. I'd be wary of waiting hours, or days.

Rich Ullsmith · Feb 8, 2012

Therefore . . .that short stack of paper I gave a 1/4 stop of preflash to . . .last summer . . .seemed like a good idea at the time.

keithwms · Feb 8, 2012

If you are seeing changes over 10-15 minutes when working up a batch of ten prints then perhaps your developer is exhausting. Please also be careful to keep exposed papers in complete darkness after exposure- a typical enlarger has a lot of light leaks, plus the light reflected off the paper can be very substantial, and can easily fog exposed papers lying around.

Hours should be totally fine.

eddie · Feb 8, 2012

Keith- I used fresh developer, and exposed paper was kept in a separate paper safe. No chance for inadvertent exposure. This experience was with the Ilford papers. I have successfully bulk processed Forte Poly WT fiber papers without any variations, using the same routine.

keithwms · Feb 8, 2012

Yikes, that's bad Eddie! I've never seen anything of the sort, although I tend to use slavich papers and I rarely do ten at a time. There's probably a lot of variation between papers...

tkamiya · Feb 8, 2012

Um....

If you take some negatives and print a few but not develop until later, how would you know you have the right exposure? Unless you are working with negs you have everything already down pat already, it doesn't seem to be a workable solution....

In addition, shared environment like school darkrooms, there are enough variance even with the same enlarger that is not under your personal control. I would think you run the great risk of wasting lots of paper....

I would expose - develop - and fix, then quick wash. Then come back and do a full wash later (in the same day).

Photo Engineer · Feb 8, 2012

There are two ways to approach this.

1. Expose and process immediately. There is no LIK.

2. Expose and hold a set period of time such as 1 or 2 hours, then process. LIK has moved the exposure but it is probably pretty stable by this time, at least enough for this type of work. With big batches of paper, we used this method at EK.

1 and 2 will generally give different results.

and 3. Expose and freeze or expose and keep for 1 - 2 hours then freeze. These will keep almost forever. This is how Kodak makes test strips or standard exposures.

PE

eddie · Feb 8, 2012

I think the OP needs to test before making this part of his workflow. I'd probably expose 5 sheets. I'd immediately develop the first, before exposing the other 4 sheets. Then, I'd wait 1 hour, 2 hours, 24 hours, and 72 hours (to account for no darkroom access during a weekend). The only way to know is to see what happens.

It seems that the specific paper may play a part, too.

EKDobbs · Feb 9, 2012

tkamiya said:
Um....

In addition, shared environment like school darkrooms, there are enough variance even with the same enlarger that is not under your personal control. I would think you run the great risk of wasting lots of paper....

It's not a shared environment. I took a free class period to set up my own darkroom in the of a very large closet in the graphic arts department. No one but me ever touches anything.

And yes, I plan to work with negatives that I've already got pinned down in terms of exposure time.

EKDobbs · Feb 9, 2012

eddie said:
I think the OP needs to test before making this part of his workflow. I'd probably expose 5 sheets. I'd immediately develop the first, before exposing the other 4 sheets. Then, I'd wait 1 hour, 2 hours, 24 hours, and 72 hours (to account for no darkroom access during a weekend). The only way to know is to see what happens.

It seems that the specific paper may play a part, too.

I'm very new to printing and the process in general; a little bit of environmental error in the prints is probably indistinguishable to me from my own mistakes in processing. I just wanted to make sure the prints wouldn't completely fog up or lose the image while waiting to be developed.

brianmquinn · Feb 9, 2012

You should also read this over
(there was a url link here which no longer exists)

Pat Erson · Feb 11, 2012

"This experience was with the Ilford papers"

Interesting! To save time I do my contact-sheets (on Ilford RC paper) in bulk (I expose 25-30 sheets then I process them 5 by 5). I only do the "expose and process immediately" procedure at the very beginning of the printing session (to check the exposure time and the chemistry).

I realized that the bulk of my sheets was never as good as these very 1st tests. Now I know why? Don't delay!

David A. Goldfarb · Feb 11, 2012

In response to the original question, I don't think a few hours is going to be a problem.

In response to the situation of a difference in a stack of ten prints, I don't think that's a latent-image keeping issue. Much more likely is change in developer chemistry with each print (Adams suggests factorial development as a solution to this), or variation in the brightness of the enlarger bulb from the first print to the last, particularly if you're using cold light without a compensating timer and/or other methods of keeping the illumination even (bulb heater, properly warmed up, or leaving the bulb on to warm up and controlling exposure with a black card or shutter).

Photo Engineer · Feb 11, 2012

David;

It could be either, but in some cases it is actually LIK.

PE

brianmquinn · Feb 11, 2012

I had the same ideas years ago when I discovered this issue. I always thought that the image on paper would be as stable as the image on film. I was wrong. When I was printing I would work late into the night and often I would take an hour nap and return to work. At first I thought I must have been too sleepy before and that is why my prints looked different. I did tests and even went so far as to mix up several batches of developer one every hour. I found that my paper developer would go bad in a few hours even without use. By bad I do not really mean bad but that it would not print EXACTLY the same as a fresh batch after as few as 4 hours in the tray (note that I was only mixing about 250ml per batch for the test and it was in an 8x10 tray so it had lots of chance to oxidize). The loss of developer strength as due to age alone, there was no usage.

Then I tested the latent image on the paper. I found that delaying developing the print by as little as 15 minutes altered the image. I later read ( I did not test this ) that the latent image changes rapidly during the first hour or so, then slower during the first day, then less for the next week then little after that except for the gradual loss of contrast and build up of fog. So the take home message I got is expose and develop paper ASAP. In your case it may be a few hours but that is ASAP in your case. It will work. But keep in mind that it is not a typical situation.

keithwms · Feb 12, 2012

Anybody know how the results differ for developer-incorporated papers versus others? RC vs. fiber?

I only work with matte fiber...

brianmquinn · Feb 12, 2012

Developer-incorporated papers? Good question. I can't recall exactly what papers I was using when I did my test.

brianmquinn · Feb 12, 2012

Here is a link to some graphs for the Latent image stability of AGFA MULTlCONTRAST PREMIUM. Not the paper I was using but the only thing I found on the web that is hard data.

http://www.plumeltd.com/artzone/paperzone/amcp.htm

Perhaps this paper is better than most and that is why they published these graphs.

How long after exp. can print last without dev?

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